Optical device

ABSTRACT

A first optical device is adapted to couple to a second optical device along a coupling direction and includes two spaced apart pairs of leading and trailing pads, such that when the first optical device lands and slides on a landing surface of the second optical device to optically couple to the second optical device, and for each pair of leading and trailing pads, the leading pad prevents any debris on the landing surface from collecting on the trailing pad. Upon full coupling of the first optical device with the second optical device, the leading pads do not make contact with the landing surface. The first optical device may be, for example, an optical ferrule or a cradle having a recess adapted to receive an optical ferrule.

BACKGROUND

Optical connectors can be used for optical communications in a varietyof applications including telecommunications networks, local areanetworks, data center links, and internal links in computer devices.Optical connectors can include optical ferrules.

SUMMARY

In some aspects of the present description, an optical ferrule isprovided. The optical ferrule has opposing major top and bottom surfaceswhere the major top surface includes a first groove and a lightredirecting surface and the major bottom surface includes discretespaced apart first and second platforms arranged along a matingdirection of the optical ferrule. The light redirecting surface isconfigured to receive light along a first direction from an opticalwaveguide received and supported in the first groove and redirect thereceived light along a different second direction. The redirected lightexits the optical ferrule though the bottom surface. During a mating ofthe ferrule with a mating optical ferrule, the first and secondplatforms of the ferrule slide against corresponding respective firstand second platforms of the mating ferrule. Upon full mating of theferrule with the mating ferrule, the second platforms of the ferrule andthe mating ferrule remain in contact with and rest on each other, andthe first platform of neither ferrule makes contact with the otherferrule.

In some aspects of the present description, an optical ferrule includinga first protrusion disposed between a second protrusion and a leadingend of the ferrule is provided. The ferrule is configured to mate with amating optical ferrule including a first protrusion disposed between asecond protrusion and a leading end of the mating ferrule, such thatwhen the ferrule fully mates with the mating ferrule, the secondprotrusions of the ferrule and the mating ferrule make contact with andrest on each other, the first protrusions of the ferrule and the matingferrule are disposed on opposite sides of the second protrusions, andthe first protrusion of each ferrule faces a major surface of the otherferrule without contacting it.

In some aspects of the present description, an optical ferrule includingpluralities of first pads and second pads arranged on a same major firstsurface of the ferrule is provided. Each pad extends from the majorfirst surface to a pad surface. When the ferrule fully mates with amating ferrule, the pad surfaces of the second, but not the first, padsmake contact with and rest on a major surface of the mating ferrule.

In some aspects of the present description, an optical ferrule includinga plurality of pairs of leading and trailing pads is provided. During amating of the ferrule with a mating optical ferrule and for each pair ofleading and trailing pads, the leading pad slides against a majorsurface of the mating ferrule to prevent any debris on the major surfacefrom collecting on the trailing pad, and upon full mating of the ferrulewith the mating ferrule, the trailing, but not the leading, pads makecontact with the major surface of the mating ferrule.

In some aspects of the present description, a first optical deviceadapted to couple to a second optical device along a coupling directionis provided. The first optical device includes two spaced apart pairs ofleading and trailing pads, such that when the first optical device landsand slides on a landing surface of the second optical device tooptically couple to the second optical device, and for each pair ofleading and trailing pads, the leading pad prevents any debris on thelanding surface from collecting on the trailing pad. Upon full couplingof the first optical device with the second optical device, the leadingpads do not make contact with the landing surface.

In some aspects of the present description, an optical ferrule includinga plurality of pairs of wiping and mating pads is provided. When theoptical ferrule mates with a mating optical ferrule including aplurality of pairs of wiping and mating pads, the wiping pads of theferrule and the mating ferrule wipe the mating pads of the matingferrule and the ferrule, respectively, and upon full mating of theferrule with the mating ferrule, the mating pads of the ferrule and themating ferrule contact one another.

In some aspects of the present description, an optical ferrule includinga plurality of pairs of first and second pads is provided. When theoptical ferrule mates with a mating optical ferrule comprising aplurality of pairs of first and second pads, the first pads of theferrule and the mating ferrule contact a surface of the mating ferruleand the ferrule, respectively, and upon full mating of the ferrule withthe mating ferrule, the second, but not the first, pads of the ferrulecontact the surface of the mating ferrule.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B are schematic top and bottom perspective views,respectively, of an optical ferrule;

FIG. 2 is a schematic cutaway perspective view of a portion of theoptical ferrule of FIGS. 1A-1B;

FIG. 3 is a schematic perspective view of a portion of a bottom surfaceof the optical ferrule of FIGS. 1A-1B;

FIGS. 4A-4C are schematic plan views of major bottom surfaces of opticalferrules;

FIG. 5A is a schematic perspective view of an optical ferrule disposedproximate a mating optical ferrule;

FIG. 5B is a schematic illustration of an optical assembly including anoptical ferrule mated with a mating optical ferrule;

FIG. 6A is a schematic cutaway perspective view of a portion of anoptical ferrule and a portion of a mating optical ferrule at a pointduring mating;

FIG. 6B is a schematic cutaway perspective view of a portion of anoptical ferrule and a portion of a mating optical ferrule fully matedwith the optical ferrule;

FIG. 7 is a schematic illustration of a cross-section through a recessformed in the bottom surface of an optical ferrule;

FIG. 8 is a schematic cross-sectional view of a portion of a bottomsurface of an optical device;

FIG. 9A is a schematic cross-sectional view of portions of majorsurfaces of an optical device and an optical mating device mated to oneanother;

FIG. 9B is a schematic cross-sectional view of portions of majorsurfaces of an optical device and an optical mating device duringmating;

FIG. 10A is a schematic cross-sectional view of a portion of a majorsurface of an optical ferrule;

FIG. 10B is a schematic cross-sectional view of the portion of the majorsurface of the optical ferrule of FIG. 10A and a corresponding portionof a major surface of a mating optical ferrule when the ferrule andmating ferrule are fully mated;

FIG. 11A is a schematic cross-sectional view of a portion of an opticalferrule;

FIG. 11B is a schematic cross-sectional view of the portion of theoptical ferrule of FIG. 11A beginning to mate with a correspondingportion of a mating optical ferrule;

FIG. 11C is a schematic cross-sectional view illustrating the portionsof the optical ferrule and mating ferrule of FIG. 11B at an intermediatepoint during mating;

FIG. 11D is a schematic cross-sectional view illustrating the portionsof the optical ferrule and mating ferrule of FIG. 11B fully mated withone another;

FIG. 12A is a schematic cross-sectional view of a portion of an opticalferrule;

FIG. 12B is a schematic cross-sectional view illustrating the portion ofthe optical ferrule of FIG. 12A during mating with a correspondingportion of a mating optical ferrule;

FIG. 12C is a schematic cross-sectional view illustrating the portionsof the optical ferrule and mating ferrule of FIG. 12B fully mated withone another;

FIG. 13A is a schematic cross-sectional view of a portion of an opticalferrule;

FIG. 13B is a schematic cross-sectional view of the portion of theoptical ferrule of FIG. 13A during mating with a corresponding portionof a mating optical ferrule;

FIG. 13C is a schematic cross-sectional view of the portions of theoptical ferrule and mating ferrule of FIG. 13B fully mated with oneanother;

FIG. 14 is a schematic cross-sectional view of portions of an opticalferrule and a mating optical ferrule fully mated with one another;

FIGS. 15A-15C are schematic top views of cradles; and

FIG. 16 is a schematic top view of an optical assembly including anoptical ferrule mated with a cradle.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings that form a part hereof and in which various embodiments areshown by way of illustration. The drawings are not necessarily to scale.It is to be understood that other embodiments are contemplated and maybe made without departing from the scope or spirit of the presentdescription. The following detailed description, therefore, is not to betaken in a limiting sense.

Optical ferrules can be used to optically couple optical fibers to otheroptical fibers. For example, optical fibers attached to an opticalferrule can be optically coupled to optical fibers attached to a matingoptical ferrule when the optical ferrule and the mating ferrule aremated. Optical ferrules can also be used to optically couple opticalfibers to waveguides in a photonic integrated circuit (PIC), forexample. For example, optical fibers attached to an optical ferrule canbe optically coupled to a PIC when the optical ferrule is mated with acradle mounted to the PIC. When an optical ferrule is mated to a matingferrule or to a cradle, mating surfaces of the optical ferrule andmating ferrule or cradle typically contact one another. For example, themating surfaces may contact each other over a substantially planarinterface that may be, for example, roughly 3 mm long along a matingdirection. If a single 5 micron diameter debris (e.g., dust) particle istrapped in the substantially planar interface, it would generate anangular error of about 0.1 degrees or larger. However, single modeexpanded beam optical interconnect devices are often sensitive toangular errors on the order of 0.1 degrees and such angular errors cancause significant insertion loss, for example. It has been found,according to some embodiments of the present description, that includingpairs of pads, protrusions, or platforms on the mating surface(s) ofoptical ferrules or other optical devices prevents debris from producingsubstantial alignment errors. For example, in some embodiments, anoptical ferrule includes a plurality of pairs of leading and trailingpads, such that during a mating of the ferrule with a mating opticalferrule including a corresponding plurality of pairs of leading andtrailing pads, and for each pair of leading and trailing pads, theleading pad of the ferrule slides against a trailing pad of the matingferrule and a leading pad of the mating ferrule slides against thetrailing pad of the ferrule. In some embodiments, upon full mating, thebottom surfaces of the ferrule and mating ferrule contact each otheronly along the trailing pads which have been cleared of debris by thesliding of the leading pads against the trailing pads during mating.

FIGS. 1A-1B are schematic top and bottom perspective views,respectively, of an optical ferrule 200 having opposing major top andbottom surfaces 10 and 20. The major top surface 10 includes a groove 30and a light redirecting surface 40. In the illustrated embodiment, themajor top surface 10 includes a plurality of grooves 30 extending alonga first direction (x-direction) and arranged along an orthogonaldirection (y-direction). The plurality of grooves 30 may be V-grooves,U-grooves, or Y-grooves, for example. Y-grooves are described in PCTpublication Nos. WO 2017/066022 (Haase et al.) and 2017/066018 (Haase etal.), for example. In the illustrated embodiment, the light redirectingsurface 40 includes a plurality of curved surface portions 41 (e.g.,reflectors formed in the light redirecting surface 40) where each curvedsurface portion 41 is disposed to receive light from an opticalwaveguide received in a groove corresponding to the curved surfaceportion. The curved surface portions 41 may reflect by total internalreflection, for example. Optical ferrules having a light redirectingsurface with curved surface portions are described in U.S. Pat. Publ.No. 2018/0259718 (Haase et al.), for example. The major surfaceincluding the groove 30 and light redirecting surface 40 may be referredto as the major top surface, and the major surface through which lightexits the optical ferrule 200 may be referred to as the major bottomsurface regardless of the orientation of the optical ferrule 200.

The optical ferrule 200 has a leading end 210 and a trailing end 212.The leading end 210 of the ferrule 200 is the end that first approachesa mating ferrule during mating of the ferrule 200 with the matingferrule. The trailing end 212 is the end of the ferrule opposite theleading end 210 along a coupling direction or mating direction(x-direction) of the ferrule.

FIG. 2 is a schematic cutaway perspective view of a portion of theoptical ferrule 200. The light redirecting surface 40 is configured toreceive light 31 from an optical waveguide 32 received and supported ina first groove 30 along a first direction (x-direction) and redirect thereceived light along a different second direction (minus z-direction).The redirected light 33 exits the optical ferrule though the bottomsurface 20. In some embodiments, the bottom surface 20 includes a windowregion 50 disposed between narrower front 60 and wider rear 70 portionsof the bottom surface 20, and the redirected light 33 exits the opticalferrule 200 through the window region 50 of the bottom surface 20. Inother embodiments, the window region 50 is disposed between front andrear portions 60 and 70 having a substantially same width. The frontportion 60 is disposed closer to the leading end 210 and the rearportion 70 is disposed farther from the leading end 210. The windowregion 50 may be a recessed optical window and may be coated with anantireflective coating. Optical ferrules having a window region aredescribed in U.S. Pat. Publ. No. 2018/0259718 (Haase et al.), forexample.

FIG. 3 is a schematic perspective view of a portion of the bottomsurface 20 of the optical ferrule 200. The bottom surface 20 includespads, protrusions or platforms 90 and 100. In some embodiments, thebottom surface 20 includes discrete spaced apart first and secondplatforms 90 and 100 arranged along a mating direction (x-direction) ofthe optical ferrule 200. In some embodiments, the bottom surface 20includes a first protrusion 90 disposed between a second protrusion 100and a leading end 210 of the ferrule 200. In some embodiments, theoptical ferrule 200 includes pluralities of first pads 90 and secondpads 100 arranged on a same major first surface 20 of the ferrule 200,which also includes a major second surface 10 opposite the major firstsurface 20, where each pad extends from the major first surface 20 to apad surface 91 and 101. In some embodiments, the pad surfaces 91 and 101of the first and second pads 90 and 100 are substantially coplanar(e.g., any deviation of the pad surfaces from being coplanar may besubstantially less than (e.g., less than 0.5 or 0.2 times) the lengthsand widths of the pads 90 and 100). The pads 90, which are closer to theleading end 210, may be referred to as leading pads and the pads 100,which are farther from the leading end 210, may be referred to astrailing pads. In some embodiments, the leading pads of the ferrule anda corresponding mating ferrule are for wiping the trailing pads of themating ferrule and the ferrule, respectively, and the trailing pads ofthe ferrule and the mating ferrule are for resting on one another. Thefirst or leading pads, platforms, or protrusions may be referred towiping pads, platforms, or protrusions, and the second or trailing pads,platforms, or protrusions may be referred to as mating pads, platforms,or protrusions. In some embodiments, the optical ferrule 200 includes aplurality of pairs of leading and trailing pads 90 and 100. In someembodiments, the narrower front portion 60 of the bottom surface 20defines a recess 80 therein. In some embodiments, the pads or platforms90 and 100 are formed in the recess 80 and extend higher than the bottomsurface 20 a adjacent the recess 80.

The first and second platforms 90 and 100 have respective first andsecond widths W1 and W2 along a width direction (y-direction),orthogonal to the mating direction (x-direction), of the optical ferrule200. In some embodiments, light 31 is received along a first direction(e.g., x-direction) and the light redirecting surface 40 redirects thereceived light 31 along a second direction (e.g., minus z-direction)that is substantially orthogonal (e.g., orthogonal to within 30, or 20,or 10, or 5, or 3 degrees) to the width and mating directions. In someembodiments, the first direction is parallel to the mating direction. Insome embodiments, the second width W2 is smaller than the first widthW1. In some embodiments, the second width W2 is smaller than the firstwidth W1 by at least about 10 microns, or at least about 20 microns, orat least about 30 microns, or at least about 40 microns, or at leastabout 50 microns. In some embodiments, the second width W2 is smallerthan the first width W1 by at least about 5% or at least about 10%. Itmay be desired for W1 to be larger than W2 so that the first platform 90wipes substantially all of the surface of the second platform 100 of themating ferrule even if there is some misalignment, for example. Thefirst and second platforms 90 and 100 have respective first and secondlengths L1 and L2 along the mating direction (x-direction) of theoptical ferrule 200. In some embodiments, the second length L2 is largerthan the first length L1. In some embodiments, the second length L2 isat least about 1.5 times or at least about 2 times the first length. Insome embodiments, the second length L2 is larger than the first lengthL1 by at least about 10 microns, or at least about 20 microns, or atleast about 25 microns.

Various arrangements of pairs of the first and second platforms 90 and100 are possible. Example arrangements are schematically illustrated inFIGS. 4A-4C. Other arrangements are also possible. For example,additional pairs may be included, or the pairs may be arranged inalternate patterns, or one or both of the first and second platforms 90and 100 may have a different size and/or shape. The pairs of the firstand second platforms 90 and 100 schematically illustrated in FIGS. 4A-4Ccan optionally be disposed in a recess defined in the major surface. Therecess may be included to provide additional space for debris, forexample.

FIG. 4A is a schematic illustration of a major surface 420 a of anoptical ferrule including four pairs 95 a-95 d of leading and trailingpads 90 and 100. In the illustrated embodiment, the pads 90 are arrangedin a regular array and the pads 100 are arranged in a regular array. Anysuitable number of pairs of leading and trailing pads can be included(e.g., one pair, two pairs, three pairs, four pairs, or more pairs). Twoor more pairs may be included to provide greater mating stability thanprovided by a single pair. In some embodiments, only two pairs of padsare included. In other embodiments, three or more pairs, or four or morepairs are included.

FIG. 4B is a schematic illustration of a major surface 420 b of anoptical ferrule including two pairs 95 a-95 b of leading and trailingpads 90 and 100. As described further elsewhere herein (see, e.g., FIGS.11A-11D), the major surface 420 b may further include a plurality ofrecesses 445 such that upon full mating of a ferrule having the majorsurface 420 b with a corresponding mating ferrule, each recess 445 isdisposed to receive, but not contact, a corresponding leading pad of themating ferrule while the trailing pads 100 contact the correspondingmajor surface of the mating ferrule. In some embodiments, an opticalferrule receives light from a waveguide along a first direction (e.g.,x-direction) and redirects the received light along a different seconddirection (e.g., z-direction), and the two pairs 95 a and 95 b ofleading and trailing pads 90 and 100 are aligned along a third direction(e.g., y-direction) substantially orthogonal to the first and seconddirections.

FIG. 4C is a schematic illustration of a major surface 420 c of anoptical ferrule including three pairs 95 a-95 c of leading and trailingpads 90 and 100. Each pair of leading and trailing pads 90 and 100 mayhave a same size and shape, or some leading and trailing pads may have adifferent size or shape than others. For example, the leading andtrailing pads of pair 95 c in FIG. 4C may have a different size and/orshape than the leading and trailing pads of the other pairs.

FIG. 5A is a schematic illustration of the optical ferrule 200 disposedproximate a mating optical ferrule 200′. FIG. 5B is a schematicillustration of an optical assembly 201 including first and secondoptical ferrules 200 and 200′ mated to one another. FIGS. 6A-6B areschematic cutaway perspective views of a portion of the optical ferrule200 and a portion of the mating optical ferrule 200′ at a point duringmating and upon full mating, respectively, of the ferrule 200 with themating ferrule 200′. During mating, the ferrule 200 and mating ferrule200′ move relative to one another along the mating directions 211 and211′. In some embodiments, the optical ferrule 200 includes a first pad,platform, or protrusion 90 disposed between a second pad, platform, orprotrusion 100 and a leading end 210 of the ferrule 200, and the matingoptical ferrule 200′ includes a first pad, platform, or protrusion 90′disposed between a second pad, platform, or protrusion 100′ and aleading end 210′ of the mating ferrule 200′. In some embodiments, duringa mating of the ferrule 200 with a mating optical ferrule 200′, thefirst and second platforms 90 and 100 of the ferrule 200 slide againstcorresponding respective first and second platforms 90′ and 100′ of themating ferrule 200′, and upon full mating of the ferrule 200 with themating ferrule 200′, the second platforms 100 and 100′ of the ferrule200 and the mating ferrule 200′ remain in contact with and rest on eachother, and the first platform (90 and 90′) of neither ferrule makescontact with the other ferrule. In some embodiments, during the matingof the optical ferrule 200 with the mating ferrule 200′, the firstplatform 90 of the optical ferrule 200 dips into a recess 80′ of thebottom surface 20′ of the mating ferrule 200′ prior to contacting thefirst platform 90′ of the mating ferrule 200′, where the first andsecond platforms 90′ and 100′ of the mating ferrule 200′ are formed inthe recess 80′ of the bottom surface 20′ of the mating ferrule 200′. Insome embodiments, when the ferrule 200 fully mates with the matingferrule 200′, the second protrusions 100 and 100′ of the ferrule 200 andthe mating ferrule 200′ make contact with and rest on each other, thefirst protrusions (90 and 90′) of the ferrule and the mating ferrule aredisposed on opposite sides of the second protrusions 100 and 100′, andthe first protrusion of each ferrule faces a major surface (20, 20′) ofthe other ferrule without contacting it. In some embodiments, when theferrule 200 fully mates with a mating ferrule 200′, the pad surfaces 101(see FIG. 3 ) of the first (100), but not the second (90), pads makecontact with and rest on a major surface 20′ of the mating ferrule 200′.

It has been found that including pairs of leading and trailingprotrusions, platforms, or pads can improve alignment between matedoptical devices by preventing debris from degrading alignment accuracy.In some embodiments, the leading pads 90 of the ferrule 200 wipe thetrailing pads 100′ of the mating ferrule 200′ during mating and thismechanically pushes any debris initially present on the trailing pads100′ off the trailing pads 100′ so that the debris does not interferewith the alignment of the ferrule 200 and mating ferrule 200′.Similarly, in some embodiments, the leading pads 90′ of the matingferrule 200′ wipe the trailing pads 100 of the ferrule 200 during matingand this mechanically pushes any debris initially present on thetrailing pads 100 off the trailing pads 100 so that the debris does notinterfere with the alignment of the ferrule 200 and mating ferrule 200′.

In some embodiments, the first platforms (90, 90′) of the ferrule 200and the mating ferrule 200′ are wiping platforms for wiping the secondplatforms (100′, 100) of the mating ferrule 200′ and the ferrule 200,respectively, and the second platforms (100, 100′) of the ferrule 200and the mating ferrule 200′ are mating platforms for resting on oneanother. In some embodiments, after the wiping platforms (90, 90′) ofthe ferrule 200 and the mating ferrule 200′ wipe the mating platforms(100′, 100) of the mating ferrule 200′ and the ferrule 200,respectively, the mating platforms (100, 100′) of the ferrule 200 andthe mating ferrule 200′ rest on one another. In some embodiments, afterthe wiping platforms (90, 90′) of the ferrule 200 and the mating ferrule200′ wipe the mating platforms (100′, 100) of the mating ferrule 200′and the ferrule 200, respectively, the mating platforms (100, 100′) ofthe ferrule 200 and the mating ferrule 200′ wipe one another and come torest on one another.

In some embodiments, the optical ferrule 200 includes a plurality ofpairs of wiping and mating pads 90 and 100 such that when the opticalferrule 200 mates with a mating optical ferrule 200′ including aplurality of pairs of wiping and mating pads 90′ and 100′, the wipingpads of the ferrule 200 and the mating ferrule 200′ wipe the mating padsof the mating ferrule 200′ and the ferrule 200, respectively, and uponfull mating of the ferrule 200 with the mating ferrule 200′, the matingpads (100, 100′) of the ferrule 200 and the mating ferrule 200′ contactone another. In some embodiments, when the ferrule 200 is fully matedwith the mating ferrule 200′, the wiping pads 90 of the ferrule 200 donot contact the mating ferrule 200′. Similarly, in some embodiments,when the ferrule 200 is fully mated with the mating ferrule 200′, thewiping pads 90′ of the mating ferrule 200′ do not contact the ferrule200.

In some embodiments, the optical ferrule 200 includes a plurality ofpairs of first and second pads 90 and 100 such that when the opticalferrule 200 mates with a mating optical ferrule 200′ including aplurality of pairs of first and second pads 90′ and 100′, the first pads(90, 90′) of the ferrule 200 and the mating ferrule 200′ contact asurface (20′, 20) of the mating ferrule 200′ and the ferrule 200,respectively, and upon full mating of the ferrule 200 with the matingferrule 200′, the second (100), but not the first (90), pads of theferrule 200 contact the surface 20′ of the mating ferrule 200′. In someembodiments, the first pads (90, 90′) of the ferrule 200 and the matingferrule 200′ are wiping pads for wiping the second pads (100′, 100) ofthe mating ferrule 200′ and the ferrule 200, respectively, and thesecond pads (100, 100′) of the ferrule 200 and the mating ferrule 200′are mating pads for resting on one another. In some embodiments, afterthe wiping pads (90, 90′) of the ferrule 200 and the mating ferrule 200′wipe the mating pads (100′, 100) of the mating ferrule 200′ and theferrule 200, respectively, the mating pads (100, 100′) of the ferrule200 and the mating ferrule 200′ rest on one another. In someembodiments, after the wiping pads (90, 90′) of the ferrule 200 and themating ferrule 200′ wipe the mating pads (100′, 100) of the matingferrule 200′ and the ferrule 200, respectively, the mating pads (100,100′) of the ferrule 200 and the mating ferrule 200′ wipe one anotherand come to rest on one another.

In some embodiments, the optical ferrule 200 includes a plurality ofpairs of leading and trailing pads 90 and 100, such that during a matingof the ferrule 200 with the mating optical ferrule 200′ and for eachpair of leading and trailing pads 90 and 100, the leading pad 90 slidesagainst a major surface 20′ of the mating ferrule 200′ to prevent anydebris 49 on the major surface 20′ from collecting on the trailing pad100, and upon full mating of the ferrule 200 with the mating ferrule200′, the trailing (100), but not the leading (90), pads make contactwith the major surface 20′ of the mating ferrule 200′. In someembodiments, a first optical device (e.g., optical ferrule 200 or acradle adapted to receive optical ferrule 200) adapted to couple to asecond optical device (e.g., mating optical ferrule 200′ or a cradleadapted to receive optical ferule 200) along a coupling direction(x-direction) and includes two or more spaced apart pairs of leading andtrailing pads 90 and 100, such that when the first optical device landsand slides on a landing surface (e.g., major surface 20′ or a bottomsurface of a cavity or recess of a cradle as described further elsewhereherein) of the second optical device to optically couple to the secondoptical device, and for each pair of leading and trailing pads 90 and100, the leading pad 90 prevents any debris 49 on the landing surfacefrom collecting on the trailing pad 100. In some embodiments, upon fullcoupling of the first optical device with the second optical device, theleading pads 90 do not make contact with the landing surface.

In some embodiments, the bottom surface 20 includes a plurality ofplatforms where the plurality of platforms includes the first and secondplatforms 90 and 100. In some embodiments, the plurality of platformsincludes a plurality of spaced apart pairs of the first and secondplatforms 90 and 100. In some embodiments, during a mating of theferrule 200 with a mating optical ferrule 200′ including a correspondingplurality of platforms, the bottom surfaces of the optical ferrule 200and mating ferrule 200′ contact one another only at the pluralities ofplatforms. In some embodiments, the bottom surface 20 includes aplurality of platforms where the plurality of platforms include thefirst and second platforms 90 and 100, and upon full mating of theferrule 200 with a mating optical ferrule 200′ including a correspondingplurality of platforms, the bottom surfaces (20, 20′) of the ferrule 200and mating ferrule 200′ contact one another only at those platforms inthe pluralities of platforms that have been wiped by at least one otherplatform during mating of the ferrule 200 with the mating ferrule 200′.In some embodiments, the plurality of platforms includes a plurality ofpairs of first and second platforms 90 and 100. In some embodiments, theplatforms in the pluralities of platforms that have been wiped by atleast one other platform include only the second platforms 100 and 100′.

In some embodiments, the optical ferrule 200 and the mating ferrule 200′have a substantially same size and shape (e.g., each dimension differingby less than 30, 20, or 10 percent). In some embodiments, the opticalferrule 200 is hermaphroditic. In some embodiments, a mating surface ofan optical ferrule or other optical device and a mating surface of amating optical ferrule or other mating optical device adapted to matewith the optical ferrule or optical device have a substantially samesize and shape. For example, the bottom surfaces 20 and 20′ may have asubstantially same size and shape. In some embodiments, a portion of amating surface of an optical ferrule or other optical device thatincludes the pads, protrusions or platforms and a corresponding portionof a mating surface of the mating optical ferrule or other matingoptical device have a substantially same size and shape.

FIG. 7 is a schematic cross-sectional view through a recess 80 formed inthe bottom surface 20. In some embodiments, the narrower front portion60 of the bottom surface 20 defines the recess 80 therein, and the firstand second platforms 90 and 100 are formed in the recess and extendhigher than the bottom surface 20 a adjacent the recess.

In some embodiments, the first and second platforms 90 and 100 extendhigher than a region 20 a of the bottom surface 20 proximate the firstand second platforms by respective first and second distances d1 and d2.In some embodiments, the first and second platforms 90 and 100 areformed in the recess 80 and the region 20 a of the bottom surface 20proximate the first and second platforms 90 and 100 is adjacent to andoutside of the recess 80. In such embodiments or in other embodiments,the first and second platforms 90 and 100 extend higher than the bottomsurface 20 a adjacent the recess 80 by the respective first and seconddistances d1 and d2. In other embodiments, the first and secondplatforms 90 and 100 are not formed in a recess (see, e.g., FIG. 10A).In some embodiments, d1 is substantially equal to d2 (e.g., equal towithin about 5%, or to within about 3%, or to within about 2%). In someembodiments, d1>d2 (e.g., d1 may be at least 10% or at least 20% greaterthan d2). In some embodiments, d1 and d2 are each at least about 5microns, or at least about 10 microns, or at least about 20 microns.

FIG. 8 is a schematic cross-sectional view of a portion of a bottomsurface 820 of an optical device defining a recess 880 therein. Theoptical device may be an optical ferrule or a cradle adapted to receivean optical ferrule, for example. First, second and third pads,protrusions, or platforms 90, 100 and 92 are formed in the recess andextend higher than the bottom surface 820 a adjacent the recess. Thefirst platform 90 is disposed between and spaced apart from the second100 and third 92 platforms. In some embodiments, the first and thirdplatforms have a substantially same size and shape. In otherembodiments, the first and third platforms have a different size and/orshape.

FIG. 9A is a schematic cross-sectional view of portions of majorsurfaces 920 and 920′ of first and second optical devices mated with oneanother. The first optical device may be an optical ferrule and thesecond optical device may be another optical ferrule or a cradle adaptedto receive the optical ferrule, for example. The major surfaces 920 and920′ may have a substantially same size and shape. The major surface 920defines a recess 980 therein and the major surface 920′ defines a recess980′ therein. First and second protrusions, pads, or platforms 90 and100 are formed in the recess 980 and extend higher than the bottomsurface 920 a adjacent the recess 900, and corresponding first andsecond protrusions, pads, or platforms 90′ and 100′ are formed in therecess 980′ and extend higher (in a direction away from the body of themating optical device) than the bottom surface 920 a′ adjacent therecess 920′. The first and second platforms 90 and 100 extend higherthan the bottom surface 920 a adjacent the recess 980 by respectivefirst and second distances, where the first distance is greater than thesecond distance. The corresponding second platforms 100 and 100′ are incontact with and rest on each other. The corresponding first platforms90 and 90′ of neither optical device makes contact with the otheroptical device. The first platform 90 extends partially into the recess980′ of the mating optical device. Similarly, the first platform 90′extends partially into the recess 980 of the optical device. In someembodiments, upon full mating of the optical device (e.g., opticalferrule) with the mating device (e.g., mating optical ferrule), eachsecond pad 100 of the optical device and corresponding second pad 100′of the mating device remain in contact with and rest on each other, thecorresponding first pads 90 and 90′ of the optical device and the matingdevice are disposed on opposite sides of the second pads 100 and 100′,and the first and third pads of each device face a major surface (920,920′) of the other device without contacting it. In some embodiments,the first optical device is an optical ferrule, the second opticaldevice is a mating ferrule, and upon full mating of the ferrule with themating ferrule, the second protrusions 100 and 100′ of the ferrule andthe mating ferrule remain in contact with and rest on each other, andthe first protrusion (90, 90′) of neither ferrule makes contact with theother ferrule.

FIG. 9B is a schematic cross-sectional view of portions of the majorsurfaces 920 and 920′ of the first and second optical devices at a pointduring the mating where the first platform 90 has dipped into the recess980′ of the bottom surface 920′ prior to contacting the first platform90′. Similarly, the first platform 90′ has dipped into the recess 980 ofthe bottom surface 920 prior to contacting the first platform 90. Duringmating, the major surfaces 920 and 920′ of the ferrule and matingferrule move relative to one another along the mating directions 911 and911′.

In some embodiments, the pads or platforms are disposed on a majorsurface of an optical ferrule or optical device without being disposedin a recess defined in the major surface.

FIG. 10A is a schematic cross-sectional view of a portion of a majorsurface 1020 of an optical ferrule (or other optical device, such as acradle adapted to receive an optical ferrule). The major surface 1020includes discrete spaced apart first and second platforms 90 and 100arranged along a mating direction (x-direction) of the optical ferrule.In the illustrated embodiment, the major surface 1020 further includesan optional third platform 92. The first platform 90 is disposed betweenand spaced apart from the second 100 and third 92 platforms. The firstand second platforms 90 and 100 extend higher than a region of thebottom surface 1020 a proximate the first and second platforms 90 and100 by respective first and second distances d1 and d2, which may be inany of the ranges described elsewhere herein. In some embodiments,2d2>d1>d2. In some embodiments, d3 is substantially equal to d1. In someembodiments, d3 is different from d1. In some embodiments, d1, d2, andd3 are each at least about 5 microns, or at least about 10 microns, orat least about 20 microns.

FIG. 10B is a schematic cross-sectional view of the portion of the majorsurface 1020 of the optical ferrule and a corresponding portion of amajor surface 1020′ of a mating optical ferrule when the ferrule andmating ferrule are fully mated. The major surface 1020′ includes first,second and third platforms 90′, 100′, and 92′, corresponding to thefirst, second and third platforms 90, 100, and 92 of the major surface1020. In some embodiments, upon full mating of the ferrule with themating ferrule, each second platform 100 of the ferrule andcorresponding second platform 100′ of the mating ferrule remain incontact with and rest on each other, the corresponding first (90 and90′) and third (92 and 92′) platforms of the ferrule and the matingferrule are disposed on opposite sides of the second platform 100 and100′, and the first and third platforms of each ferrule face a majorsurface (1020, 1020′) of the other ferrule without contacting it.

In some embodiments, upon full mating of the ferrule with the matingferrule, the trailing pads of the ferrule do not make contact with anypads on the major surface of the mating ferrule.

FIG. 11A is a schematic cross-sectional view of a portion of an opticalferrule 1100 having a leading end 1110, a trailing end 1112, and a majorsurface 1120 including a plurality of pairs of leading and trailing pads90 and 100. The optical ferrule 1100 may include additional featuressuch as waveguide alignment grooves and light redirecting surfaces thatare not shown. The major surface 1120 is a mating surface of the opticalferrule 1100 and may be referred to as a bottom major surface regardlessof the orientation of the optical ferrule 1100. One pair of the pads areshown in the illustrated cross-section. At least one other pair may bepresent in a cross-section displaced in the y-direction from theillustrated cross-section (see, e.g., FIG. 4B). FIG. 11B is a schematiccross-sectional view of the portion of the optical ferrule 1100beginning to mate with a corresponding portion of a mating opticalferrule 1100′. During mating, the ferrule 1100 and mating ferrule 1100′move relative to one another along the mating directions 1111 and 1111′.The mating ferrule 1100′ has a bottom surface 1120′ including aplurality of pairs of leading and trailing pads 90′ and 100′. FIG. 11Cis a schematic cross-sectional view illustrating the optical ferrule1100 during mating with the mating optical ferrule 1100′. FIG. 11D is aschematic cross-sectional view illustrating the optical ferrule 1100fully mated with the mating optical ferrule 1100′. Upon full mating, thetrailing pads 100 of the ferrule 1100 contact the bottom major surfaceof the mating ferrule 1100′, but do not make contact with any pads onthe major surface 1120′ of the mating ferrule 1100′. In someembodiments, the bottom major surface 1120 further includes a pluralityof recesses 1145 such that upon full mating of the ferrule 1100 with themating ferrule 1100′, each recess 1145 is disposed to receive acorresponding leading pad 90′ of the mating ferrule 1100′. Similarly, insome embodiments, the bottom major surface 1120′ includes a plurality ofrecesses 1145′ such that upon full mating of the ferrule 1100 with themating ferrule 1100′, each recess 1145′ is disposed to receive acorresponding leading pad 90 of the optical ferrule 1100.

In some embodiments, the optical ferrule 1100 includes a plurality ofpairs of first and second pads 90 and 100 such that when the opticalferrule 1100 mates with a mating optical ferrule 1100′ including aplurality of pairs of first and second pads 90′ and 100′ the first pads(90, 90′) of the ferrule 1100 and the mating ferrule 1100′ contact asurface (1120′, 1120) of the mating ferrule 1100′ and the ferrule 1100,respectively, and upon full mating of the ferrule 1100 with the matingferrule 1100′, the second (100), but not the first (90), pads of theferrule 1100 contact the surface 1120′ of the mating ferrule 1100′. Insome embodiments, the first pads (90, 90′) of the ferrule 1100 and themating ferrule 1100′ are wiping pads for wiping the second pads (100′,100) of the mating ferrule 1100′ and the ferrule 1100, respectively, andthe second pads (100, 100′) of the ferrule 1100 and the mating ferrule1100′ are mating pads for resting on the surface (1120′, 1120) of themating ferrule 1100′ and the ferrule 1100, respectively. In someembodiments, when the ferrule 1100 is fully mated with the matingferrule 1100′, the mating pads 100 of the ferrule 1100 do not makecontact with any pads on the surface 1120′ of the mating ferrule 1100′.Similarly, in some embodiments, when the ferrule 1100 is fully matedwith the mating ferrule 1100′, the mating pads 100′ of the matingferrule 1100′ do not make contact with any pads on the surface 1120 ofthe ferrule 1100.

FIG. 12A is a schematic cross-sectional view of a portion of an opticalferrule 1200 having a bottom major surface 1220 including a plurality ofpairs of leading and trailing pads 90 and 100. One pair of the pads areshown in the illustrated cross-section. At least one other pair may bepresent in a different cross-section. The optical ferrule 1200 has aleading end 1210 and trailing end 1212. FIG. 12B is a schematiccross-sectional view illustrating the portion of the optical ferrule1200 during mating with a corresponding portion of a mating opticalferrule 1200′. The mating ferrule 1200′ has a leading end 1210′, atrailing end 1212′, and a bottom surface 1220′ including a plurality ofpairs of leading and trailing pads 90′ and 100′. During mating, theferrule 1200 and mating ferrule 1200′ move relative to one another alongthe mating directions 1211 and 1211′. FIG. 12C is a schematiccross-sectional view illustrating the optical ferrule 1200 fully matedwith the mating optical ferrule 1200′. In FIG. 12C, the trailing pads100 of the ferrule 1200 contact the bottom major surface of the matingferrule 1200′, but do not make contact with any pads on the majorsurface of the mating ferrule 1200′. Upon full mating of the ferrule1200 with the mating ferrule 1200′, each trailing pad 100 of the ferrule1200 contacts the major surface 1220′ of the mating ferrule 1200′proximate a trailing end 1212′ of the matting ferrule 1200′ and eachleading pad 90 of the ferrule 1200 extends past the trailing end 1212′of the mating ferrule 1200′ such that the leading pad 90 of the ferrule1200 does not contact the mating ferrule 1200′. Similarly upon fullmating of the ferrule 1200 with the mating ferrule 1200′, each trailingpad 100′ of the mating ferrule 1200′ contacts the major surface 1220 ofthe ferrule 1200 proximate a trailing end 1212 of the ferrule 1200 andeach leading pad 90′ of the mating ferrule 1200′ extends past thetrailing end 1212 of the ferrule 1200 such that the leading pad 90′ ofthe mating ferrule 1200′ does not contact the ferrule 1200.

FIG. 13A is a schematic cross-sectional view of a portion of an opticalferrule 1300 having a major surface 1320 including a plurality of pairs95 a and 95 b of leading and trailing pads 90 and 100. In someembodiments, more pairs (e.g., three pairs, four pairs, or more pairs)of leading and trailing pads 90 and 100 are included. The plurality ofpairs of leading and trailing pads include a first pair 95 a of leadingand trailing pads 90 and 100 disposed on a first portion 1321 of themajor surface 1320 of the optical ferrule 1300 and a second pair 95 b ofleading and trailing pads 90 and 100 disposed on a different secondportion 1322 of the major surface 1320 of the optical ferrule 1300. Thefirst and second portions 1321 and 1322 are noncoplanar. In someembodiments, the first and second portions 1321 and 1322 aresubstantially planar (e.g., any radius of curvature of the first orsecond portion may be substantially larger (e.g., at least 5, or 10 or20 times larger) than a largest lateral dimension of the portion) andsubstantially parallel (e.g., within 30, 20 or 10 degrees of parallel)to one another. FIG. 13B is a schematic cross-sectional view of theportion of the optical ferrule 1300 during mating with a correspondingportion of a mating optical ferrule 1300′ and FIG. 13C is a schematiccross-sectional view illustrating the optical ferrule 1300 fully matedwith the mating optical ferrule 1300′. During mating, the ferrule 1300and mating ferrule 1300′ move relative to one another along the matingdirections 1311 and 1311′. The mating ferrule 1300′ has a major surface1320′ including a plurality of pairs 95 a′ and 95 b′ of leading andtrailing pads 90′ and 100′ corresponding to the pairs 95 a and 95 b ofleading and trailing pads 90 and 100.

FIG. 14 is a schematic cross-sectional view of a portion of an opticalferrule 1400 fully mated with a corresponding portion of a matingoptical ferrule 1400′. Optical ferrule 1400 corresponds to opticalferrule 1300 except that a length along the mating direction of thefirst portion 1421 relative to the second portion 1422 has beenincreased compared to the first and second portions 1321 and 1322. Thisallows a window region 1450 to be provided through which light receivedby an optical waveguide and redirected by a light redirecting surface(not illustrated in FIG. 14 ) of the optical ferrule 1400 exits theoptical ferrule 1400. In some embodiments, the optical ferrule 1400 andthe mating optical ferrule 1400′ are hermaphroditic.

In some embodiments of the present description, an optical device isprovided that includes at least one pair of pads, protrusions, orplatforms. The optical device may be or include an optical ferrule, anoptical connector comprising a plurality of optical ferrules such asthose described in U.S. Pat. Publ. Nos. 2018/0217337 (Smith et al.) or2018/0284357 (Nelson et al.), an optical assembly including a ferrulemated with a mating ferrule or with a mating cradle, an optical assemblyincluding an optical connector mated with a mating connector, or acradle adapted to receive an optical ferrule, for example.

In some embodiments, a first optical device adapted to couple to asecond optical device along a mating direction or coupling direction isprovided. For example, the first optical device may be any opticalferrule described elsewhere herein and the second optical device may beany corresponding mating optical ferrule. As another example, one of thefirst and second optical devices may be a cradle adapted to receive anoptical ferrule and the other of the first and second optical devicesmay be the optical ferrule.

FIGS. 15A-15C are schematic top views of cradles 1500 a-1500 c having arespective cavity or recess 1525 a-1525 c adapted to receive an opticalferrule. The recesses 1525 a-1525 c have bottom surfaces 1520 a-1520 c,respectively, including a plurality of leading and trailing platforms,protrusions, or pads 90 and 100. The recesses 1525 a-1525 c are adaptedto receive an optical ferrule along a coupling direction (x-direction)such that the optical ferrule approaches the leading pads 90 before thetrailing pads 100. The bottom surfaces 1520 a-1520 c are landingsurfaces for an optical ferrule. Conversely, the bottom surface of theoptical ferrule can be considered to be a landing surface for thecradle. The bottom surface 1520 a has two pairs 95 a and 95 b of leadingand trailing pads 90 and 100. In some embodiments, the first and secondpairs 95 a and 95 b are aligned on the bottom surface 1625 along adirection (y-direction) substantially orthogonal to the couplingdirection (x-direction). The leading and trailing pads of the first andsecond pairs 95 a and 95 b may have a same or different size or shape.The bottom surface 1520 b schematically illustrated in FIG. 15B includesthree spaced apart pairs 95 a-95 c of leading and trailing pads 90 and100. In some embodiments, the first and second pairs 95 a and 95 b arealigned on the bottom surface 1625 along a direction (y-direction)substantially orthogonal to the coupling direction (x-direction) and athird pair 95 c is noncolinear with the first and second pairs 95 a and95 b. In some embodiments, the leading and trailing pads of the firstand second pairs 95 a and 95 b have a same size and shape, and theleading and trailing pads of the third pair 95 c may have a same ordifferent size or shape than those of the first and second pairs 95 aand 95 b. For example, the leading and trailing pads of the third pair95 c may be larger than the leading and trailing pads of the first andsecond pairs 95 a and 95 b. The bottom surface 1520 c schematicallyillustrated in FIG. 15C includes four paced apart pairs 95 a-95 d ofleading and trailing pads 90 and 100. In some embodiments, the leadingand trailing pads are arranged in respective first and second regulararrays.

Other arrangements of the pairs of leading and trialing pads arepossible. For example, additional pairs may be included, or the pairsmay be arranged in alternate patterns, or the leading and/or trailingpads may have different sizes and/or shapes. The pairs of the leadingand trailing pads 90 and 100 schematically illustrated in FIGS. 15A-15Ccan optionally be disposed in a recess defined in the bottom surface asdescribed further elsewhere herein.

FIG. 16 is a schematic top view of an optical assembly 1601 including anoptical ferrule 1600 mated with a cradle 1700. The optical ferrule 1600may correspond to any of the optical ferrules described elsewhereherein. For example, the optical ferrule 1600 may include a plurality ofgrooves and light redirecting surfaces (not illustrated in FIG. 16 )such as those illustrated in FIG. 1A, 2, 5A, or 5B, for example. Thecradle 1700 may correspond to any of cradles 1500 a-1500 c, for example.In some embodiments, the cradle 1700 includes a recess or cavity forreceiving the optical ferrule 1600, and the second (100), but not thefirst (90), platform(s) of the optical ferrule 1600 contacts a bottommajor surface of the cavity. In some embodiment, the bottom majorsurface of the cradle 1700 includes first and second platformscorresponding to the respective first and second platforms of theoptical ferrule 1600, and the second platform(s) of the optical ferrule1600 contacts and rests on the second platform(s) of the cradle 1700.

An optical ferrule of the present description may be unitary. A unitarybody is a single piece construction that does not have any internalinterfaces, joints, or seams. A unitary body can be made by molding(e.g., injection molding a thermoplastic), casting or machining, forexample. Other optical devices (e.g., a cradle adapted to receive anoptical ferrule) of the present description may be unitary and/or may bemade by molding.

Terms such as “about” will be understood in the context in which theyare used and described in the present description by one of ordinaryskill in the art. If the use of “about” as applied to quantitiesexpressing feature sizes, amounts, and physical properties is nototherwise clear to one of ordinary skill in the art in the context inwhich it is used and described in the present description, “about” willbe understood to mean within 10 percent of the specified value. Aquantity given as about a specified value can be precisely the specifiedvalue. For example, if it is not otherwise clear to one of ordinaryskill in the art in the context in which it is used and described in thepresent description, a quantity having a value of about 1, means thatthe quantity has a value between 0.9 and 1.1, and that the value couldbe 1.

All references, patents, and patent applications referenced in theforegoing are hereby incorporated herein by reference in their entiretyin a consistent manner. In the event of inconsistencies orcontradictions between portions of the incorporated references and thisapplication, the information in the preceding description shall control.

Descriptions for elements in figures should be understood to applyequally to corresponding elements in other figures, unless indicatedotherwise. Although specific embodiments have been illustrated anddescribed herein, it will be appreciated by those of ordinary skill inthe art that a variety of alternate and/or equivalent implementationscan be substituted for the specific embodiments shown and describedwithout departing from the scope of the present disclosure. Thisapplication is intended to cover any adaptations or variations of thespecific embodiments discussed herein. Therefore, it is intended thatthis disclosure be limited only by the claims and the equivalentsthereof

What is claimed is:
 1. A first optical device adapted to couple to asecond optical device along a coupling direction and comprising twospaced apart pairs of leading and trailing pads, such that when thefirst optical device lands and slides on a landing surface of the secondoptical device to optically couple to the second optical device, and foreach pair of leading and trailing pads, the leading pad prevents anydebris on the landing surface from collecting on the trailing pad,wherein upon full coupling of the first optical device with the secondoptical device, the leading pads do not make contact with the landingsurface.
 2. The first optical device of claim 1 being an opticalferrule.
 3. The first optical device of claim 2 comprising opposingmajor top and bottom surfaces, the major top surface comprising a grooveand a light redirecting surface, the light redirecting surfaceconfigured to receive light along a first direction from an opticalwaveguide received and supported in the groove and redirect the receivedlight along a different second direction, the redirected light exitingthe optical ferrule through the bottom surface, the bottom surfacecomprising the two spaced apart pairs of leading and trailing pads. 4.The first optical device of claim 3, wherein the two pairs of leadingand trailing pads are aligned along a third direction substantiallyorthogonal to the first and second directions.
 5. The first opticaldevice of claim 4, wherein the bottom surface comprises three spacedapart pairs of leading and trailing pads.
 6. The first optical device ofclaim 4, wherein the bottom surface comprises four spaced apart pairs ofleading and trailing pads.
 7. The first optical device of claim 6,wherein the leading and trailing pads are arranged in respective firstand second regular arrays.
 8. The first optical device of claim 1 beinga cradle comprising a recess adapted to receive an optical ferrule, therecess having a bottom surface comprising the two spaced apart pairs ofleading and trailing pads.
 9. The first optical device of claim 8,wherein the bottom surface comprises at least three spaced apart pairsof leading and trailing pads.
 10. An optical ferrule comprising aplurality of pairs of wiping and mating pads such that when the opticalferrule mates with a mating optical ferrule comprising a plurality ofpairs of wiping and mating pads, the wiping pads of the ferrule and themating ferrule wipe the mating pads of the mating ferrule and theferrule, respectively, and upon full mating of the ferrule with themating ferrule, the mating pads of the ferrule and the mating ferrulecontact one another.
 11. The optical ferrule of claim 10, wherein whenthe ferrule is fully mated with the mating ferrule, the wiping pads ofthe ferrule do not contact the mating ferrule.
 12. An optical ferrulecomprising a first protrusion disposed between a second protrusion and aleading end of the ferrule, the ferrule configured to mate with a matingoptical ferrule comprising a first protrusion disposed between a secondprotrusion and a leading end of the mating ferrule, such that when theferrule fully mates with the mating ferrule, the second protrusions ofthe ferrule and the mating ferrule make contact with and rest on eachother, the first protrusions of the ferrule and the mating ferrule aredisposed on opposite sides of the second protrusions, and the firstprotrusion of each ferrule faces a major surface of the other ferrulewithout contacting it.
 13. The optical ferrule of claim 12 comprisingopposing major top and bottom surfaces, the major top surface comprisinga groove and a light redirecting surface, the light redirecting surfaceconfigured to receive light along a first direction from an opticalwaveguide received and supported in the groove and redirect the receivedlight along a different second direction, the redirected light exitingthe optical ferrule through the bottom surface, the bottom surfacecomprising the first and second protrusions.
 14. The optical ferrule ofclaim 12, wherein during a mating of the optical ferrule with a matingferrule, the first protrusions of the optical ferrule slides against andmoves past a corresponding first protrusion of the mating ferrule andthen the first protrusion of the optical ferrule slides against andmoves past a second protrusion of the mating ferrule corresponding tothe second protrusion of the optical ferrule.
 15. The optical ferrule ofclaim 14, wherein upon full mating of the ferrule with the matingferrule, the second protrusions of the ferrule and the mating ferruleremain in contact with and rest on each other, and the first protrusionof neither ferrule makes contact with the other ferrule.
 16. The opticalferrule of claim 12, wherein the first and second protrusions aredisposed on a bottom surface of the optical ferrule and extend higherthan a region of the bottom surface proximate the first and secondprotrusions by respective first and second distances d1 and d2.
 17. Theoptical ferrule of claim 16, wherein d1 is substantially equal to d2.18. The optical ferrule of claim 16, wherein d1>d2.
 19. The opticalferrule of claim 16, wherein the bottom surface defines a recesstherein, the first and second protrusions being formed in the recess,the region of the bottom surface proximate the first and secondprotrusions being adjacent to and outside of the recess.
 20. The opticalferrule of claim 16, wherein d1 and d2 are each at least about 5microns.